JAR-OPS Landing Wet runway

[PEI_3721]

As per Fella.
Dry landing distance is 1.67 of manufacturers’ value (equivalent to landing within 60% of available distance for the weight / prevailing conditions for jet aircraft. See JAR-OPS 1.515).

Wet landing distance is 1.93 of manufacturers’ value, i.e. 1.67 * 1.15 (115% of dry, JAR-OPS 1.520 “The landing distance available is at least 115% of the required landing distance, determined in accordance with JAR–OPS 1.515” ).

See slides 26-27 and speakers notes in Managing Threats and Errors During Approach and Landing.
Also, remember that in practical terms the wet landing distance factor only provides a safety margin in specific conditions and thus may not be as large as that for landing on dry runways. In addition, wet runway conditions can vary much more than dry, the depth of water (up to the contaminated definition) and the runway texture (grooved or good / poor friction surface) can significantly reduce the safety margin. See reports from Transport Canada which indicate that in extreme conditions safety margins of 2.2-2.4 may be required to provide the equivalent safety margin as for dry runways.